Abstract

Background

In Japan, both incidence and mortality rates of cancers have continuously increased
and medical costs are growing more rapidly than the overall economy of Japan. However,
there is no consensus threshold for cost-effectiveness in medical care, and few studies
have investigated cost-effectiveness of medical care in Japan. The present study was
to determine the direct costs of molecular-targeting drugs that were recently approved
in Japan through simple and quantitative calculations. Thus, we calculated an incremental
cost-effectiveness ratio (ICER) and the cost per life-year gained (LYG) by using reported
data from randomized clinical trials for various cancers.

Methods

Between 2008 and 2011, we reviewed seven molecular-targeting drugs that were approved
for treatment of five cancers in Japan. These drugs included Bevacizumab, sorafenib,
sunitinib, temsirolimus, Lapatinib, and panitumumab. Direct cost, ICER, and LYG of
the drugs were estimated from the randomized phase III clinical trial data referred
to in package leaflets. Effectiveness was defined as the prolongation of both median
overall survival (OS) and progression-free survival (PFS). Costs were calculated as
those of molecular-targeting drugs. Subsequently, ICER was based on 1-month increases
in both OS and PFS periods and 1% increases in OS, and LYG was determined.

Results

Direct costs ranged from ¥724,804 ($9,060) to ¥1,506,628 ($18,833). ICERs of the drugs
ranged from ¥724,804 ($9,060) to ¥1,506,628 ($18,833) for a 1-month increase in OS.
For each month of PFS, ICERs ranged from ¥372,243 ($4,653) to ¥7,399,877 ($92,498).
The costs of Bevacizumab and sorafenib for treatment of HCC per 1% increase in OS
were ¥376,657 ($4,708) and ¥313,733 ($3,922), respectively. LYG ranged from ¥8,697,650
($108,721) to ¥18,079,530 ($225,994).

Conclusions

Some molecular-targeting drugs are not cost-effective. Considering ethical and moral
issues, we should establish economic endpoints to approve new drugs in Japan.